1. Field of the Invention
The invention relates to a device for the simultaneous display of data in the form of a page on a display apparatus during a given time interval, comprising a data connection for receiving data signals, a foreground memory having an input which is connected to the data connection and an output which is connected to an input of the display apparatus, said foreground memory being adapted to store the data of a page during said interval, said device furthermore comprising a control member having an output which is connected to an input of a control device for unblocking the input of the foreground memory. Such a device would serve as a display terminal in a so-called Teletext system.
2. Description of the Prior Art
Teletext is the generic name for systems utilizing the normal television channels for transmitting written or graphic material which can subsequently be displayed on customary, simple receivers, possibly after a simple intermediate operation. The material to the displayed is organized according to pages, it being possible to display exactly one page on the display apparatus. The Teletext system has been in extensive experimental use in Great Britain since September 1974 on the public broadcast system. An extensive documentation on how to adapt a commercial TV receiver to the system has been described in a series of articles in Wireless World, a magazine primarily intended for radio amateurs in the following issues: November 1975, p. 498, December 1975, p. 563, January 1976, p. 37, February 1976, p. 47, March 1976, p. 75, April 1976, p. 64, May 1976, p. 64, June 1976, p. 53. In principle, a plurality of pages could be displayed together, but in that case they would be smaller. The pages are transmitted by a transmitter in a predetermined sequence. The user selects one page of data to be displayed either without priority or on the basis of reference data contained in a previously displayed page, or the user selects the pages successively like when reading a book.